'FLASK_APP' is not recognized as an internal or external command, operable program or batch file. code example
Example 1: 'flask' is not recognized as an internal or external command, operable program or batch file.
set PATH=C:\Users\YOUR_USER_NAME\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\Scripts
Example 2: run flask app from command line
set FLASK_APP=<app_name>
$env FLASK_APP=<app_name>
flask run
Example 3: flask commands
from flask_script import Manager
from myapp import app
manager = Manager(app)
@manager.command
def hello():
print "hello"
if __name__ == "__main__":
manager.run()